CVE-2026-59335 (CVSS 8.7)

Description

Improper handling of case sensitivity (CWE-178) in the identity zone authorization check in the Identity Zone Endpoint in Cloud Foundry UAA allows a remote authenticated attacker holding only the zones.write authority to bypass the intended restriction that this authority does not grant access to the privileged uaa (system) identity zone, by referring to the zone identifier in a non-lowercase form (e.g. UAA) in the request path and body. The authorization layer performs a case-sensitive comparison against the system zone identifier, while the underlying MySQL persistence layer resolves identifiers case-insensitively under its default collation, so the request is authorized incorrectly and is then resolved against the real system zone record. This allows the attacker to overwrite the system zone's JWT signing key with attacker-controlled key material, forge JWTs claiming the admin client and administrator scopes, and fully compromise UAA and any Cloud Foundry deployment that trusts it. This issue only affects UAA deployments backed by MySQL using its default collation; PostgreSQL and HSQLDB backends are not affected.

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CVSS v3.1 Score

8.7

HIGH

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N

EPSS — Exploit Prediction

0.0030

Probability of exploitation

0.23%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-178 CWE-178

References

Other References

https://www.cloudfoundry.org/blog/cve-2026-59335-uaa-case-insensitive-check-bypass/

Frequently Asked Questions

What is CVE-2026-59335? +

Improper handling of case sensitivity (CWE-178) in the identity zone authorization check in the Identity Zone Endpoint in Cloud Foundry UAA allows a remote authenticated attacker holding only the zones.write authority to bypass the intended restriction that this authority does not grant access to the privileged uaa (system) identity zone, by referring to the zone identifier in a non-lowercase form (e.g. UAA) in the request path and body. The authorization layer performs a case-sensitive comparison against the system zone identifier, while the underlying MySQL persistence layer resolves identifiers case-insensitively under its default collation, so the request is authorized incorrectly and is then resolved against the real system zone record. This allows the attacker to overwrite the system zone's JWT signing key with attacker-controlled key material, forge JWTs claiming the admin client and administrator scopes, and fully compromise UAA and any Cloud Foundry deployment that trusts it. This issue only affects UAA deployments backed by MySQL using its default collation; PostgreSQL and HSQLDB backends are not affected. It has a CVSS v3.1 base score of 8.7 (HIGH).

How severe is CVE-2026-59335? +

CVE-2026-59335 has a CVSS v3.1 score of 8.7 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0030, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-59335? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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